Free Wireless Daily NewsletterFierceWireless is the first place industry insiders turn to find out what’s shaping and revolutionizing the wireless landscape. Every business day, executives at carriers and service providers rely on FierceWireless to stay up to speed on:

Verizon Wireless (NYSE: VZ) indicated it has struck deals with both Sprint (NYSE: S) and T-Mobile US (NYSE:TMUS) to interconnect VoIP traffic, which could be a precursor to Voice over LTE roaming agreements.

In an FCC filing, Verizon stated that it and Sprint "have entered into agreements for the exchange of voice traffic in IP format, as have Verizon Wireless and T-Mobile." The carrier did not go into more detail about the agreements in the filing and Verizon representatives did not offer more information about the agreements.

Verizon disclosed the deals as part of a long filing rebutting claims made by OSS specialist Comptel in various FCC proceedings. Verizon noted that it has negotiated deals for the exchange of VoIP traffic between its incumbent LECs, which provide Verizon's FiOS Digital Voice service, and eight other companies: Comcast (NASDAQ: CMCSA), Vonage, Bandwidth.com, Millicorp, Intermetro, Broadvox, BrightLink and 365 Wireless.

The disclosure about the deals with Sprint and T-Mobile is significant because it could indicate Verizon is already laying the groundwork for voice roaming when voice traffic moves to LTE and becomes just another IP application. Today, VoLTE services in the U.S. are still just getting off the ground, but their deployment and adoption is likely going to grow in the years ahead. With VoLTE, voice traffic goes over IP instead of the circuit-switched voice network.

T-Mobile US (NYSE:TMUS) has launched VoLTE in the Seattle area for customers using three devices, the LG Electronics G Flex and Samsung Electronics Galaxy Note 3 and Galaxy Light. T-Mobile plans to roll out VoLTE to more T-Mobile customers throughout the year but has not given a timeframe for doing so.

AT&T Mobility (NYSE: T) also just launched VoLTE via the Samsung Galaxy S4 mini in select areas in Illinois, Indiana, Minnesota and Wisconsin. The carrier said it will expand to additional markets and phones in the future.

Verizon recently reiterated it plans to launch VoLTE sometime this year on a nationwide basis, and said that when it launches the service the carrier will offer a "robust line" of VoLTE-capable smartphones and video calling services.

Sprint (NYSE: S), for its part, has said it is in no rush to launch VoLTE. The company will rely on its CDMA network and EVRC-NW-powered HD Voice technology for voice calling services for the foreseeable future.

THE LIBRARY: WEBINAR

At the current state of mobile networks, operators need to aggressively pursue multiple avenues to respond to rising demand for speed and throughput. This webinar will discuss how to update and add capacity to existing sites using tower mounted amplifiers, multi-band and same band combiners, interference mitigation filters, and ultra wideband antennas. Register to watch now!